This invention relates to noise reduction devices for textile machinery, and is particularly directed to the reduction of noise which results from the mounting of spindles on the frames of textile machinery.
In the past, the spindles on spinning frames and twisters were attached to the spindle base rails by extending the base of the spindle through a hole in the spindle base rail of the textile machine. The spindle has a sufficiently large diameter that a shoulder thereon engages the top of the base rail. The lower extension of the spindle is threaded, so that a nut may be tightened over the threaded portion of the spindle base and against the underside of the base rail. Under normal conditions, there is consequently metal to metal contact, when the spindles are mounted in this manner, so that a resonating effect is produced, and any noise created by the rotating spindle is amplified.
The noise produced by a single rotating spindle is of course not very great, but in a processing room, for example, for the production of thread or yarn, there may be many hundreds or thousands of such rotating spindles. As a consequence, the noise produced by the spindles may be very great.
For example, spindles mounted in the above manner may result in noise levels in a room exceeding 90 db.
There are of course many well known noise reducing techniques, and modern textile equipment may readily be designed to take advantage of such techniques, to reduce the room noise levels to a tolerable value. The useful life of textile machinery, such as thread and yarn spinning frames and the like, is quite long, however, so that full replacement of the equipment is neither economically justified nor warranted.
There have been recent interests in the reduction of noise level in factories, from the standpoint of safety and health, and standards have been established with respect to the length of time that a worker may be present in a room at given noise levels. The noise level in the rooms of a textile mill has been adequately high in the past, that workers were not permitted to spend full working days in the rooms, without ear muffs or the like. This is of course undesirable from a standpoint of operating and maintaining the equipment, since, particularly, with the less modern equipment, manual operations such as doffing and donning may be required. The solution of requiring the workers to wear ear muffs has not been found to be satisfactory or accepted by the workers.
The present invention is therefore directed to the provision of noise reduction means, for reducing the above described spindle noise in textile machines. While the invention is particularly directed to the provision of noise reducing means that may readily and economically be employed on existing textile machines, it will of course be apparent that the invention contemplates the extension of the same concept to new equipment, if desired.
Briefly stated, in accordance with the invention, a pair of washers are provided for each spindle of the textile machines. The washers are placed to engage opposite sides of the machine frame surrounding the spindle hole, so that the spindle and nut assembly clamp the washers therebetween, substantially isolating the spindles from the machine frame, for the transmission of noise and resonating effects.
Specifically, noise reducing washers which have been found to be particularly satisfactory for the above purpose, are comprised of a pair of hard plastic washers, for example, of nylon, between which a soft elastic washer, for example of rubber, is sandwiched. The rubber washer has a plurality of holes extending axially therethrough at a common radius, and each of the outer nylon washers has alternating projections and holes at the same radius. The noise reducing washer is assembled so that the projections of one outer washer are aligned with the holes of the other outer washer, and extend into the corresponding holes of the intermediate rubber washer.